February 08, 2023
For deer-sized game, practical all-around calibers (bullet diameters) are probably limited to just five: .257, .264 (6.5mm), .277 (6.8mm), .284 (7mm), and .308 (7.62mm).
There are numerous cartridges in each, with unique case dimensions and performance characteristics. We all have our favorites to debate around the campfire, but nobody can say the 7mm, .284-inch, isn't an excellent deer caliber.
Plenty of bullet weight and frontal area, with heavier bullets offering high Sectional Density (SD) for deep penetration. With good aerodynamics, 7mm bullets hold velocity and energy well, so faster 7mms are excellent in open country. Recoil is a matter of gun weight, bullet weight and velocity, so it is not always true that 7mms kick more than smaller calibers (or less than .30s). However, by manipulating those factors, this is generally true.
After .30, 7mm is America's most popular hunting caliber, with numerous 7mm cartridges from which to pick, in velocity ranges from moderate to very fast. I've hunted with most of them, but nobody needs one of each. If you're in the market for a new 7mm, here are seven worth considering.
The original 7mm cartridge was developed by Peter Paul Mauser in 1892, and widely adopted as a military cartridge. In 1898, American troops faced the 7x57 in Cuba, and the Brits faced it in South Africa. Both came away with enough respect for the 7x57 that it has been a fairly popular sporting cartridge ever since. It was renamed .275 Rigby for the British market, but 7x57 and .275 Rigby are identical, a mild-mannered, light-recoiling cartridge, 140-grain bullet at around 2700 fps. It is not a long-range cartridge, but performs like gang busters on deer-sized game. I don't use the 7x57 in big, open country, but out to 250 yards or so, it's wonderful, with mild report and recoil.
Provided I don't need reach, the 7x57 is my favorite whitetail cartridge, but 1980's 7mm-08 Rem, based on the .308 Win case necked down, is identical in performance. Because it is loaded to higher pressure for modern actions, the 7-08 is slightly faster, 140-grain at 2800 fps. The 7mm-08 has two advantages:
First, it fits into a short action; the 7x57 does not. Second, the 7mm-08 is more popular, with a greater selection of loads. To get a 7x57 to strut its stuff, handloading is necessary. So, if you want a mild-recoiling, butt-kicking medium-range deer cartridge, the 7mm-08 is the horse to ride. Honestly, I don't have one; I prefer the tradition of the 7x57. However, my wife and both daughters have 7mm-08s, primarily because of availability of factory loads.
Since the 1920s, there were wildcat versions of the "7mm-06." The European 7x64 Brenneke is similar, but the American factory version is the .280 Remington, introduced in 1957. It is, honestly, probably the very best cartridge based on the .30-06 case, 140-grain bullet approaching 3000 fps.
Unfortunately, the .280 Rem has never been especially popular. Factory loads are hard to find, and it is chambered to few current rifles. That doesn't mean it isn't good, but it's not common. My buddy, Texan John Stucker is a .280 guy. He likes it because, being contrarian, it's different. More famous fans include Jim Carmichel, Steve Hornady, and Todd Smith. I've had several flings with the .280 and have taken some nice bucks with it. Great cartridge, but it's really for guys who choose not to follow the crowd.
.280 Ackley Improved
Parker Otto Ackley (1903-1989) experimented with every available case, removing body taper to increase powder capacity, and sharpening shoulder angle to increase efficiency. Ackley's rule for an "improved" cartridge: Standard factory ammo can be used; all you're doing is fire-forming, then you reload the cases with proper dies.
The .280 AI was one of Ackley's most popular wildcats. Recently, it has started to take off, now chambered to some production rifles, with factory loads from Hornady and Nosler. No, you won't find them at the local hardware store (no more than .280 Rem), but it has a following, and attributes. It is almost as fast as the 7mm Rem Mag (140-grain bullet over 3000 fps), with more compact ammo. Like its parent .280 Rem, it's a contrarian cartridge, but I like it. My friend Lee Newton, an avid Ruger collector, now uses it for all his deer hunting. My .280 AI is also a Ruger No. One. Accurate and hard-hitting, I see it more of a Western or open-country cartridge. It is adequate for any deer that walks … at any sensible range.
7mm Winchester Short Magnum
Short actions reduce gun weight, also bolt throw. Neither advantage is dramatically important to me, but matter greatly to some. There are two short-action 7mm "magnums" that essentially duplicate 7mm Rem Mag (and .280 AI) performance, 140-grain bullet at about 3000 fps. These two are: 7mm Winchester Short Magnum (WSM), introduced in 2001, and the 7mm Remington Short Action Ultra Mag (RSAUM), introduced a year later.
With more case capacity, the 7mm WSM is slightly faster, but not enough to matter to any buck, boar, or ram. Remington's short-action cartridges were in retaliation to Winchester, but they had another problem. The WSM case is a bit long to fit into Remington's little Model Seven action. So, they were stuck, and we were stuck with two very similar short-action 7mm cartridges. End result is neither is popular. That said, if you like short actions and like "magnum 7mm performance," both are great little cartridges.
My son-in-law, Brad Jannenga, has a custom 7mm WSM that is his go-to. He loves it, and has used it for big bucks and much more. I shot a big whitetail in Arkansas when the 7mm RSAUM was new, dropped it like the hammer of Thor. This past Kansas season, Erin Tremaine took one of our best bucks with her 7mm RSAUM. She isn't in love with her cartridge—neither is Brad—but their rifles shoot extremely well. The short-action argument is valid, but if you choose one of these, better lay in emergency ammo and don't tap into it.
7mm Remington Magnum
Introduced in 1962, Remington's Big Seven became the world's most popular 7mm cartridge, and the world's most popular cartridge to be called a "magnum." The 7 Rem Mag, with a 140-grain bullet at something over 3000 fps, is a wonderful cartridge. Perhaps more appropriate for mule deer, but awesomely effective for open-country whitetails.
Today, the Big Seven is not as popular as it was—perhaps too many newer 7mm cartridges—but don't discount it. The 7mm Rem Mag is still a world-standard hunting cartridge. For a medium-range, easy-to-shoot whitetail cartridge, my personal choice remains the 7x57, but I'd recommend the 7mm-08 to you. If I wanted a mule deer cartridge, or hunted whitetails in open country, I'd steer you toward the 7mm Remington Magnum, just on sheer availability.
It is not the only choice. The .280 Rem and .280 AI fill the same niche, and Roy Weatherby's 7mm Wby Mag has been around since 1945. Same parent case as the 7mm Rem Mag, .300 H&H shortened, body taper removed, necked down to 7mm. Through the 1950s, pundits were clamoring for a fast 7mm, but they already had one in the 7mm Wby Mag. Out of pride and/or courtesy, I suppose the big boys weren't willing to tread on Weatherby.
Both the 7mm Wby and Rem Mags fit standard-length actions. The Wby is faster, but that's primarily because Weatherby's factory loads, from Norma, are loaded a bit hotter than domestic 7mm Rem Mag ammo. Flip a coin, the two are too close to call but, obviously, availability goes to Remington's Big Seven, still one of the great 7mm hunting cartridges.
The new kid on the block, just released by Hornady. The new 7mm PRC is not the fastest 7mm; 28 Nosler, 7mm Shooting Times Westerner (STW), and 7mm Remington Ultra Mag (RUM) are faster.
Two things: First, the faster 7mms are all over bore capacity. This has little to do with accuracy, and the larger cases deliver greater speed. However, as you push a bullet down a bore too small to efficiently burn the powder, efficiency and propellent selection decrease, and barrel life is reduced. Second, understand that the 7mm PRC is all about heavy bullets and fast-twist barrels. Until now, most 7mm rifles, cartridges, and loads have used lighter bullets (140 to maybe 165 grains). The 7mm PRC is designed for maximum efficiency with today's heavy, low-drag bullets. The first loads use 180-grain bullets at 2960 fps. Although awesome at long range, bullets this heavy aren't essential for most deer hunting. Using them does no harm, except recoil will be the same as a .30-caliber with a 180-grain bullet at the same velocity, so much the same as a .300 Win Mag.
I am excited by the efficiency and heavy-bullet performance of the 7mm PRC. Just understand what you are getting, and base it on what you need. For most of my whitetail hunting, I'm still happy with my 7x57s. Where I hunt, and for the shots I take, they still do what I need done.